The present invention relates generally to a method for building a structure for vibration attenuation of structural elements in a vehicle.
A suspension system absorbs road shock and other vibrations, while providing for a smooth and comfortable ride. The suspension system responds to wheel disturbances and reacts to maintain wheel contact with the road surface. Damping systems produce opposing forces which counteract vibrations produced during vehicle operation. Damping forces provided by the suspension system cancel resonant responses which cause unwanted motion. In the prior art, fluid filled shock absorbers in the suspension system are used to counteract these vibrations. As fluid is commonly utilized to provide damping, the damping force increases approximately proportionally with the viscosity of the damping fluid. A drawback to prior damping systems is that these shock absorbers are passive in nature.
Hence, there is a need in the art for an improved structure for vibration attenuation of structural elements in a vehicle.
This invention relates to a method for building a structure for vibration attenuation of structural elements in a vehicle.
The structure includes an upper sheet, a lower sheet and an intermediate sheet perforated with a plurality of holes. The sheets, preferably made of steel, are stamped to a desired shape. A plurality of elastic strips are positioned such that a layer of elastic strips are located between each the sheets when assembled. The sheets are assembled so that the intermediate sheet is positioned substantially between the upper sheet and the lower sheet, and viscous fluid is dispersed between each layer. The sheets are secured, preferably by welding, sealing the viscous fluid within the structure. Movement of the fluid through the holes provides vibration attenuation and damping when the structure is compressed, extended, bent or submitted to vibrations.
In a second embodiment, a continuous elastic sealing strip is positioned between and substantially inside the edges of the upper and lower sheets, but outside the edge of the intermediate sheet, the sealing strip containing the fluid. The structure is preferably secured, such as by a plurality of rivets positioned between the edge of the inner and outer sheet and the sealing strip.
In a third embodiment, electro-rheological or magnetic-rheological fluid is utilized. Piezo-elements positioned in the suspension system provide an electrical input to the fluid in the structure to change the state of the fluid and alter the relative stiffness of the structure in response to a proportional increase in load.
Accordingly, the present invention provides a method for building a structure for vibration attenuation of structural elements in a vehicle.
These and other features of the present invention will be best understood from the following specification and drawings.